“ legal restrictions on hate speech would create more problems than they would solve”
I think that you fail to make a case to support that statement, only pointing to Rwanda of all places as proof that hate laws don’t work. That’s like pointing to Iran as proof that religious freedom laws don’t work…
Just look North to Canada, a country that is comfortable in saying that hate speech is too much free speech, and enshrining it in law. And no dictator has taken it over for the last 30 years.
As for having hate speech legislation running afoul of the first amendment, it seems that some categories are already considered outside of free speech (https://www.law.cornell.edu/wex/fighting_words), so that does not seem like a sensible reasoning either.
I don’t think this is an either/or argument as you make (one must either make laws to curb it; or work on curbing it instead). They go hand in hand, with the laws providing the longer term security that this is now an established rule of the land (as opposed to a case-law exception to the existing freedom of speech amendment).
Now what you do need is sufficient rallying around this cause to propel it forward, law or no law. And that is the part that seems lacking right now in the US.